Abstract

Genetic monitoring and preservation of gene pools of wild and domestic animals remains one of the main problems of modern genetics. At the same time for the majority of aboriginal rocks there is no exact information about the condition of the populations of these animals, their number, distribution, no description of genotypic and phenotypic characteristics. Domestic aboriginal rocks are practically not studied at the molecular genetic level using modern DNA technologies. A unique informational vacuum has been created, which does not allow, on the one hand, to fully assess the uniqueness of the breed diversity of Ukraine, and, on the other hand, to use the biological resources of local breeds for their effective use in breeding programs.

The study of the gene pool of local (aboriginal) breeds of cattle is interesting in terms of originality of the genetic structure and the identification of polygens responsible for the high adaptive qualities of animals. At the same time, according to experts from the United Nations World Food Organization (FAO), the main obstacle to the development of animal breeding programs is the lack of information on the genetic structure of populations, since the risk status based on the number of livestock can not reflect the whole picture of the destruction of the gene pool .

Gray Ukrainian breed of cattle, as a representative of a group of indigenous native species, is an interesting object of population research in relation not only to adaptation characteristics, but also genetic mechanisms that provide a phenotypic manifestation of certain characteristics of productivity.

Today, more than three dozen world breeds of cattle are characterized by PCR-PDR methods. As a test system for studying the genetic diversity of the gray Ukrainian cattle breed, data on the allele polymorphism of the BoLA-DRB3 gene of the major histocompatibility complex, which participates in the formation of the immune response of the organism to viral and bacterial infections, has been used.

Exzone 2 of the BoLA-DRB3 gene of bovine animals is of particular interest for two reasons:

- high functional significance of the gene in the formation of the immune response of the organism;

- high level of polymorphism.

The purpose of the work was to study the peculiarities of the distribution of alleles and genotypes of the BoLA-DRB3 gene in the gray Ukrainian breed of cattle.

Materials and methods of research. Blood samples (n = 72) from gray cows of Ukrainian breed from farms of the State Enterprise "Marcheevo" (Kherson oblast) and DP "Polivanivka" (Dnipropetrovsk region) were investigated. Molecular genetic research was carried out on the basis of the Genetics Laboratory of the Institute of Animal Breeding and Genetics named after MV Zubets of NAAS.

The polymorphism of the BoLA-DRB3 alleles arose evolutionarily due to the need for a variable cellular receptor structure in relation to foreign protein antigens and has wide geographic and intracerebral variability. Indicators of the variability of alleles in the BoLA-DRB3 gene in different breeds of cattle confirm the high level of its polymorphism. According to foreign authors, the highest variety of the spectrum of the alleles of the gene BoLA-DRB3 was found in Kalmyk - 36, Yaroslavl - 28, and Mongolian cattle – 35 alleles. The average prevalence of alleles was found in the Kostroma (23) and zeuvite (22) cattle. A low level of genetic diversity for the BoLA-DRB3 gene was noted in Yakut cattle - 14 alleles. The allelic spectrum of two domestic cattle populations is determined. In the Ukrainian black-and-white dairy cattle found 28, and red-ryaboy – 22 alleles.

In a sample of 72 animals of gray Ukrainian breed found 22 alleles out of 54 described by Van Eijk and 5 alleles that are not included in this list: * jab, * jba, * jbb, * nad, * nda. Of the 27 identified 13 alleles, they are determined with a frequency of less than 1%. 6 alleles BoLA-DRB3 * 16, * 12, * 06, * jba, * 15 and * 24 were the most informative ("significant" alleles, which are determined with a frequency of more than 4%).

The feature of the sample being sampled is the high frequency of the BoLA-DRB3.2 * 16 allele. Significant prevalence of one or two alleles over others occurs precisely in aboriginal rocks. Thus, in the Yakut cattle, the allele * 29, which manifests itself with the frequency of 42.9%, and in the Kostroma breed, is * 10, the share of which is 22.5%.

The total frequency of the "weighty" alleles BoLA-DRB3.2 * 16, * 12, * 06, * jba, * 15 and * 24 accumulates 75% of the allelophone of the gray Ukrainian breed, indicating its low genetic diversity. The low level allele diversity of the investigated breed by the BoLA-DRB3 locus is due to inbred depression, which occurs in the case of a long isolation of the population and its low population.

We used the Shannon-Wiener index (H`) to quantitatively map the allele polymorphism of gray cattle. For the gray Ukrainian breed of cattle, the Sennon-Wiener index is 3.26.

At present, 54 alleles have been detected using a polymerase chain reaction, based on the definition of genotypes of animals. As a rule, a high level of allelic diversity of the BoLA-DRB3 gene causes a wide range of possible genotypes. The largest number of genotypes is observed in black-and-white and Yaroslavl cattle (72 variants), and the smallest – in Yakut (18 variants) [7]. In the gray Ukrainian breed, only 35 BoLA-DRB3 genotypes are found (Table 2). It is difficult to distinguish the predominant genotype in this breed. So, with frequency > 5% only 1 genotype * 16 / * 16 (5.25%) is presented.

Conclusions.

Thus we obtained data on the frequency of detection of the BoLA-DRB3 gene in a population of gray Ukrainian cattle breeds:

Of the 54 types found 22, listed under Van Eijk M. J. and 5 types that are not included in this list: * jab, * jba, * jbb, * nad, * nda.

Aural spectrum is uneven. With a frequency of more than 4%, 6 alleles are detected: * 06, * 12, * 15, * 16, * 24 and * jba). The frequency range varies from 43.06 to 4.86%.

Alel * 16 is significantly superior to others. It manifests itself in more than 43% of cases. The high frequency is represented by allele * 12 (9.72%).

Studied the distribution of genotypes in gray cattle. Only 35 BoLA-DRB3 genotypes are installed.